An international group which focuses on child prostitution has said that foreign child sex tourists are starting to operate in Vietnam.

The Australia-based group End Child Prostitution, Pornography and Trafficking Australia said there is credible evidence to suggest that children under the age of sixteen are being targeted by sex tourists travelling to Vietnam.

It's running a project funded by the Australian government to alert tourism workers in Vietnam, Cambodia and Thailand to the dangers of child prostitution.

Recent estimates say that nearly a third of all sex workers in Vietnam are under the age of sixteen. There have been no prosecutions of foreign nationals in Vietnam for sex crimes against children.